Just starting out - Bullet Comparitor

[royinidaho]

Been studying you folks' methods. Getting confused..... See the 270izzy thread......

I suppose the answer is yes, but I gotta ask.....

Can a Stoney-point bullet comparator be used to measure just the bullet dimensions in addition overall loaded length to the ogive?

Also, what is/are dual comparitors? and how used?

Before I order some more high priced bullets I want to figure out this bullet sorting thing with the bullets I have on the shelf and see if it makes a difference. Also I guess I gotta order a stone point thinger........ Just wanna know how to use it before it arrives so I don't look so dumb in front of my shootin buddy /ubbthreads/images/graemlins/wink.gif

 

[abinok]

Roy,
Im not an expert on sorting bullets, but hopefully some of those will chime in shortly, in the mean time....
Yes the SP can be used to measure a variety of things on bullets.
With the comparitor you can measure length form the base to the ogive, and with the "dual comparitors" aka, two of the comparitors attached to the caliper jaws opposite one another, you can measure bearing surface length.
Before anybody points it out, the sp does not measure anything exactly the way it says it does. The comparitor simply has a hole bored through an interchangeable insert, that when closed on a bullet, indexes from a point of a certian diameter on the bullet surface. This does not give you a "bearing surface" length exactly, but a number very close to bearing surface length that can be compared bullet to bullet. There are tools that can measure things like bearing surface length very accurately, and precicely, but they are quite expensive compared to the sp comparitor, and im not convinced that they are that much more accurate.
If you want to sort by base to ogive length, you just need the comparitor body, and the insert of the approprate caliber.
If you want to sort by bearing surface, you need two comparitor bodies, and two inserts of the approprate caliber.
The sp comparitor comes in handy for lots of other measunring tasks too. For instance, they are a nifty way to sort rimfire ammnition by rim thickness, or headspace on fired brass.
Hope that made sense /ubbthreads/images/graemlins/grin.gif